HadCM3-SRESB1HadCM3 Climate Simulation - IPCC emission scenario SRESB1Met Office Hadley CentreHadCM3-SRESB12007-02-01Exeter/Devon/UKMet Office Hadley Centremodel gridInvestigatorData OwnerTimJohnstim.johns@metoffice.gov.uk+44 (0) 1392 886901+44 (0) 1392 885681Met Office Hadley CentreFitzroy RoadExeterDevonEX1 3PBUKMetadata ContactMarkElkingtonmark.elkington@metoffice.gov.uk+44 (0) 1392 884835+44 (0) 1392 885681Met Office Hadley CentreFitzroy RoadExeterDevonEX1 3PBUKEARTH SCIENCEAtmosphereAerosolsEARTH SCIENCEAtmosphereAtmospheric PressureEARTH SCIENCEAtmosphereEnergy/Radiation BalanceEARTH SCIENCEAtmosphereAtmospheric TemperatureEARTH SCIENCEAtmosphereAtmospheric Water VapourEARTH SCIENCEAtmosphereAtmospheric WindsEARTH SCIENCEAtmosphereCloudsEARTH SCIENCEAtmospherePrecipitationEARTH SCIENCECryosphereFrozen GroundEARTH SCIENCECryosphereSea IceEARTH SCIENCECryosphereSnow/IceEARTH SCIENCELand SurfaceFrozen GroundEARTH SCIENCELand SurfaceLand TemperatureEARTH SCIENCELand SurfaceSoilsSoil MoistureEARTH SCIENCELand SurfaceSoilsSoil TemperatureEARTH SCIENCETerrestrial HydrosphereGround WaterSoil MoistureEARTH SCIENCETerrestrial HydrosphereSnow/IceClimatology/Meteorology/Atmosphere1989-12-012100-11-01360 DayComplete90S90N180W180E0 km50 Pa0 km5.2 km2.75 degrees in the atmosphere3.75 degrees in the atmosphere250 km - < 500 km or approximately 2.5 deg -
< 5.0 deg19 levels in the atmosphere30 minutes in atmosphere - typically averaged on day,
month, season or yearDaily Climatology1.25 degrees in the ocean1.25 degrees in the ocean100 km - < 250 km or approximately 1 deg -
< 2.5 deg10m to 616m (20 levels in the ocean)10 meters - < 30 meters1 hour in ocean - typically averaged on day, month, season
or yearDaily ClimatologyHadCM3Hadley Centre Coupled Model Version 3Registration with the British Atmospheric Data Centre is
required before this data set can be accessed.(http://badc.nerc.ac.uk)This dataset must only be used for scientific purposes unless
specific authorisation is given by the Met Office. The Met Office must be
acknowledged in any reproduction of data, publication of papers, reports,
presentations and other literature arising from the use of these data.British EnglishMet Office Hadley CentreGB/NCAS/BADCBritish Atmospheric Data Centre, NERC Centres for Atmospheric
Science, United Kingdomhttp://badc.nerc.ac.uk/HadCM3-SRESB1Data Centre ContactBADC Supportbadc@rl.ac.uk+44 (0) 1235 446432+44 (0) 1235 446314Space Science and Technology DepartmentR25 - Room 2.122Rutherford Appleton LaboratoryChilton, Nr DidcotOxfordshireOX11 0QXUKonline FTP65GbPPNone (for scientific use)online FTP65GbnetCDFNone (for scientific use)Pope, V., M.L. Gallani, P.R. Rowntree, R.A. Stratton, (2000) The
impact of new physical parameterisations in the Hadley Centre climate model:
HadAM3. Climate Dynamics, 16, pp123-146.Gordon, C., C. Cooper, C.A. Senior, H.T. Banks, J.M. Gregory, T.C.
Johns, J.F.B Mitchell and R.A. Wood (2000) The simulation of SST, sea ice
extents and ocean heat transports in a version of the Hadley Centre coupled moel
without flux adjustments. Climate Dynamics, 16, pp147-168.Johns, T.C., J.M. Gregory, W.J. Ingram, C.E. Johnson, A. Jones, J.A.
Lowe, J.F.B. Mitchell, D.L. Roberts, D.M.H Sexton, D.S Stevenson, S.F.B. Tett,
M.J. Woodage (2003) Anthropogenic climate change for 1860 to 2100 simulated with
the HadCM3 model under updated emissions scenarios. Climate Dynamics, 20,
583-612.The Hadley Centre Coupled Model Version 3 was developed from the earlier
HadCM2 model. Various improvements were applied to the 19 level atmosphere model and
the 20 level ocean model and as a result the model requires no artificial flux
adjustments to prevent excessive climate drift. The atmosphere and ocean exchange
information once per day, heat and water fluxes being conserved exactly. Momentum
fluxes are interpolated between atmosphere and ocean grids so are not conserved
precisely, but this non-conservation is not thought to have a significant effect.
The main differences from the previous HadCM2 model are a significantly more
sophisticated radiation scheme; the inclusion of the direct impact of convection on
momentum; and the inclusion of a new land surface scheme that includes a better
representation of evaporation, freezing and melting of soil moisture.
The
HadCM3 model was used by the Hadley Centre to provide input for the IPCC Third
Assessment Report.
The SRESB1 simulation contained in this dataset includes
forcings of green house gases (including methane) that are consistent with
historical levels and the future IPCC SRESB1 scenario, sulfur (direct and indirect
forcing, sulphur chemistry without natural DMS and SO2 background emissions;
anthropogenic SO2 emissions from surface and high level only) and
tropospheric/stratospheric ozone. The SRESB1 scenario represents the lowest green
house gas concentrations of the six SRES scenarios.VIEW EXTENDED METADATAhttp://www.metoffice.gov.uk/research/link/metadata/HadCM3_SRESB1.xmlMore detailed metadata on the model configuration and parameters is
available in XML format.GET DATAhttp://badc.nerc.ac.uk/Users must register with the British Atmospheric Data Centre to
access this data set.CEOS IDN DIF9.72008-05-212008-05-212010-05-21FalseHadCM3NumSimwww.metoffice.gov.ukLINKGCMThe Hadley Centre Hadley Centre Coupled Model Version 3 was
developed from the earlier HadCM2 model in the period 1997-2000. Various
improvements were applied to the 19 level atmosphere model and the 20 level
ocean model and as a result the model requires no artificial flux
adjustments to prevent excessive climate drift. The atmosphere and ocean
exchange information once per day, heat and water fluxes being conserved
exactly. The main differences from the previous HadCM2 model are a
significantly more sophisticated radiation scheme; the inclusion of the
direct impact of convection on momentum; and the inclusion of a new land
surface scheme that includes a better representation of evaporation,
freezing and melting of soil moisture. It improved on the resolution
available from previous Hadley Centre models and included support for
interactive couplings between the atmosphere and ocean and the biosphere,
atmospheric chemistry, the sulphur cycle and atmospheric aerosols. The
HadCM3 model was used by the Hadley Centre to provide input for the IPCC
Third Assessment Report.Pope, V., M.L. Gallani, P.R.
Rowntree, R.A. Stratton, (2000) The impact of new physical parameterisations
in the Hadley Centre climate model: HadAM3. Climate Dynamics, 16, pp123-146.Gordon, C., C. Cooper, C.A.
Senior, H.T. Banks, J.M. Gregory, T.C. Johns, J.F.B Mitchell and R.A. Wood
(2000) The simulation of SST, sea ice extents and ocean heat transports in a
version of the Hadley Centre coupled moel without flux adjustments. Climate
Dynamics, 16, pp147-168.Johns, T.C., J.M. Gregory, W.J.
Ingram, C.E. Johnson, A. Jones, J.A. Lowe, J.F.B. Mitchell, D.L. Roberts,
D.M.H Sexton, D.S Stevenson, S.F.B. Tett, and M.J. Woodage (2003)
Anthropogenic climate change for 1860 to 2100 simulated with the HadCM3
model under updated emissions scenarios. Climate Dynamics, 20,
583-612.AtmosphereAtmosphereThe atmospheric model component in HadCM3 is a version of
the UKMO unified forecast and climate model configured with a horizontal
grid spacing of 2.5° x 3.75° and 19 vertical levels using an Arakawa B
gird and hybrid vertical co-ordinates. The time step is 30 min.
Davies, T., M. J. P. Cullen,
A. J. Malcolm, M. H. Mawson, A. Staniforth, A. A. White, and N. Wood,
(2005) A new dynamical core for the Met Office’s global and regional
modelling of the atmosphere. Quarterly Journal Royal Meteorology
Society, 131, 1759–1782.Radiation SchemeRadiationSchemeHadCM3 uses the new radiation scheme developed by
Edwards and Slingo (1996) and modified by Cusack et al. (1999). This
has six shortwave bands and eight longwave bands. As well as
including the effects of CO2, H2O, and O3 it also includes the
effects of O2, N2O, CH4, CFC11 and CFC12. The model uses trace gas
values appropriate for the period 1979-1988. HadCM3 also includes
the developments made by Cusack et al. (1998) to include the effects
of background aerosols. Further improvements in HadCM3 are that ice
crystals and water droplets are treated separately in the radiation
scheme. Cloud overlaps are treated consistently in the shortwave and
the longwave regions: in particular, layer cloud in the shortwave is
no longer reduced to three layers. Edwards, J.M. and A.
Slingo (1996) Studies with a flexible new radiation code. I:
choosing a configuration for a large-scale model. Quarterly Journal
Royal Meteorological Society, 122, 689-719. Cusack, S., J.M. Edward,
and J.M. Crowther (1999) Investigating k-distribution methods for
parametrizing gaseous absorption in the Hadley Centre climate model.
Journal Geophysical Research 104, 2051-2057. Cusack, S., A. Slingo,
J.M. Edwards, and M. Wild (1998) The radiative impact of a simple
aerosol climatology on the Hadley Centre climate model. Quarterly
Journal Royal Meteorological Society, 124, 2517-2526.
Aerosols SchemeAerosolThree modes of sulfate aerosols (Aitken, accumulation
and dissolved in cloud droplets) with explicit parameterisations of
transfers between the different modes. Sulfur dioxide (SO2) and
dimethyl sulfide (DMS) are injected at appropriate levels. The
direct radiative effect from scattering and absorption is taken into
account. The indirect effect was implemented by prescribing cloud
changes claculated using offline models (see Johns et al., 2003).
Johns, T.C., J.M.
Gregory, W.J. Ingram, C.E. Johnson, A. Jones, J.A. Lowe, J.F.B.
Mitchell, D.L. Roberts, D.M.H Sexton, D.S Stevenson, S.F.B. Tett,
and M.J. Woodage (2003) Anthropogenic climate change for 1860 to
2100 simulated with the HadCM3 model under updated emissions
scenarios. Climate Dynamics, 20, 583-612. Land Surface SchemeLandSurfaceA new land surface scheme (Cox et al. 1999) includes a
representation of the freezing and melting of soil moisture, as well
as surface runoff and soil drainage; the formulation of
evapotranspiration includes the dependence of stomatal resistance on
temperature, vapour pressure and CO2 concentration. The surface
albedo is a function of snow depth, vegetation type and also of
temperature over snow and ice. Cox, P. M., R. A. Betts,
C. B. Bunton, R. L. H. Essery, P. R. Rowntree, and J. Smith, 1999:
The impact of new land surface physics on the GCM simulation of
climate and climate sensitivity. Climate Dyn., 15, 183–203. Essery, R., M. Best,
and P. Cox, 2001: MOSES 2.2 technical documentation. Hadley Centre
Technical Note 30, 30 pp.Boundary Layer SchemeAtmosphereIn HadCM2, the boundary layer scheme consisted of a
local mixing scheme. This uses a mixing coefficient, which is a
function of a mixing length, the local wind shear and atmospheric
stability. It also includes a representation of non-local mixing
("rapidly mixing scheme"; Smith 1993) which uniformly distributes
the heating and moistening resulting from the divergence of the
fluxes between the surface and the top of the boundary layer. The
rapidly mixing scheme was included because, in unstable regions, the
fluxes are in fact not closely related to the local gradients. Also,
the local values of stability can be influenced by other parts of
the model, particularly the convection scheme, thereby altering the
turbulent mixing unrealistically. However, during the development of
HadCM3, it was found that the rapidly mixing scheme produced
unfavourable interactions with the transport and sink of aerosols.
Therefore, the rapidly mixing scheme is switched off in HadCM3. In
addition, the mixing length is reduced above the diagnosed top of
the boundary layer and increased in the mixed layer. Also, the
amount of freezing and melting of convective precipitation which is
not falling through downdraughts is limited so that the temperature
change due to the phase change does not increase/decrease the
temperature above or below the melting point of water.
Pope, V., M.L. Gallani,
P.R. Rowntree, R.A. Stratton, (2000) The impact of new physical
parameterisations in the Hadley Centre climate model: HadAM3.
Climate Dynamics, 16, pp123-146. Smith R. N. B (1993)
Experience and developments with the layer cloud and boundary layer
mixing schemes in the UK Meteorological Office Unified Model. Proc.
ECMWF/GCSS Workshop on Parametrization of the Cloud-Topped Boundary
Layer, ECMWF, Reading, England, 319–339.Convection SchemeConvectionSchemeThe convection scheme in the HadCM3 model was improved
by adding a parameterisation of the direct impact of convection on
momentum (Gregory et al. 1997). Moist and dry convection are
modelled using the mass-flux scheme of Gregory and Rowntree (1990)
with the addition of convective downdrafts (Gregory and Allen,
1991). Gregory, D., R. Kershaw,
and P. M. Innes (1997) Parametrisationof momentum transport by
convection II - tests in single column and general circulation
models. Quarterly Journal Royal Meteorological Society 123;
1153-1183. Gregory, J. and P.R.
Rowntree (1990) A mass flux convection scheme with representation of
cloud ensemble characteristics and stability- dependent closure.
Monthly Weather Review, 118, 1483–1506. Gregory, J. and S. Allen
(1991) The effect of convective scale downdrafts upon NWP and
climate simulations. Ninth Conference on Numerical Weather
Prediction. Denver, Colorado. American Meteorological Society pp
122-123.Gravity Wave SchemeGravityWavesA parametrisation of orographic drag (Milton and Wilson
1996) and a new gravity wave drag scheme including anisotropy of
orography, high drag states and flow blocking, and trapped lee waves
have been included (Gregory et al. 1998). Milton, S.F., and C.A.
Wilson (1996) The impact of parameterised sub-grid scale orographic
forcing on systematic errors in a global NWL model. Monthly Weather
Review, 124, 2023-2045. Gregory, D., G.J Shutts,
and J.R. Mitchell (1998) A new gravity wave drag scheme
incorporating anisotropic orography and low level wave breaking:
impact upon the climate of the UK Meteorological Office Unified
Model. Quarterly Journal Royal Meteorological Society, 124, 463-493.
Precipitation and Cloud SchemeCloudSchemeThe HadCM3 model uses a prognostic cloud scheme,
described by Smith (1990) and modified by Gregory and Morris (1996),
which diagnoses cloud ice, cloud water and cloud amount from the
primary model variables, total moisture and liquid water potential
temperature. The model uses the precipitation scheme described by
Senior and Mitchell (1993) together with the evaporation of
precipitation described by Gregory (1995). The partitioning of mixed
phase clouds into ice and water has been changed from 0 to -15 °C to
0 to -9 °C (Gregory and Morris 1996) based on evidence from
observational data. A parametrisation of the effective radius of
cloud droplets as a function of cloud water content and droplet
number concentration is also included (Martin et al. 1994).
Several parameters in the layer cloud scheme (Smith 1990)
have been altered. Cloud cover forms when the standard deviation of
the distribution of total water content in a grid box goes above a
critical relative humidity which is held at a constant value at each
level of the model. In HadCM3 this has been changed from 0.85 to 0.7
to improve the top-of-the-atmosphere (TOA) radiation balance. The
equation for liquid precipitation includes a threshold value of the
total water content, below which water does not precipitate. The
value of this threshold is different over land and ocean to
represent the different amounts of cloud condensation nuclei. In
HadCM3, these values were reduced from 8 x 10-4 to 2 x 10-4 over
land and from 2 x 10-4 to 0.5 x 10-4 over sea. In combination, these
changes improved the net TOA radiative ¯uxes when compared with
Earth Radiation Budget Experiment (ERBE) data, especially over
northern mid-latitude oceans.Smith, R. N. B. (1990) A
scheme for predicting layer clouds and their water content in a
general circulation model. Quarterly Journal of Royal Meteorological
Society, 116, 435–460.Senior C. and Mitchell J.
F. B (1993) CO2 and climate: the impact of cloud parametrisation.
Journal of Climatology, 6, 393-418.Martin G.M., D.W.
Johnson, and A. Spice (1994) The measurement and parametrisation of
effective radius of droplets in warm stratocumulus clouds. Journal
of Atmospheric Science, 51, 1823-1842. Gregory D. (1995) A
consistent treatment of the evaporation of rain and snow for use in
large-scale models. Monthly Weather Review, 123, 2716-2732. Gregory D. and D. Morris
(1996) The sensitivity of climate simulations to the specification
of mixed phase clouds. Climate Dynamics, 12, 641-651.
OceanOcean The ocean component of HadCM3 has a number of significant
modifications from previous versions of this model component. It is a 20
level version of the Cox (1984) model on a 1.25° x 1.25°
latitude-longitude grid. There are six ocean grid boxes to each
atmosphere model grid box and each high latitude ocean grid box can have
partial sea ice cover. The vertical levels are distributed to provide
enhanced resolution near to the ocean surface and are the same as those
in the previous coarser horizontal resolution version of the model.
The topography was taken from the ETOPO5 (1988) 1/12°
resolution dataset and interpolated onto the model grid. A simple
smoother was applied to remove gridscale noise.
It has been
shown that the Bryan-Cox type models are highly sensitive to the depth
of the various channels along the Greenland-Iceland-Scotland ridge. Many
of these channels are sub-gridscale and so three routes (one grid point
wide on the velocity grid) through the ridge were 'excavated'. The
Denmark Strait and Iceland-Faeroes ridge were reduced to 797.9 m (bottom
of level 12), while the Faeroe- Scotland ridge was set to 534.7 m
(bottom of model level 11). This leads to a long-term mean outflow of
approximately 8.5 Sv in the coupled simulation, compared with the
observed outflow of around 5-6 Sv (Dickson and Brown 1994). An island is
also placed at the North Pole to avoid the polar singularity in the
spherical co-ordinate system. Cox, M. D. (1984) A primitive
equation, three dimensional model of the ocean. Ocean Group Technical
Report 1, GFDL, Princeton.ETOPO5 (1988) Global 5' x 5'
depth and elevation. Technical Report, National Geophysical Data Centre,
NOAA, US Department of Commerce, Boulder, USA.. Journal of Computational
Physics, 4, 347-376Dickson, R.R. and J. Brown.
(1994) The production of North Atlantic deep water: sources, rates and
pathways. Journal of Geophysical Research, 12, 319-341.
FilteringFilteringFourier filtering is used to decrease the effective
resolution of the model at latitudes North of 74.5 degrees, to
remove spurious short-wavelength waves due to the convergence of
meridians caused by the use of a latitude-longitude grid. An
artificial Island is also included. Sunlight PenetrationRadiationSchemeA two band scheme (one more penetrative) from Paulson
and Simpson (1977), assuming pure water type 1B with coefficients
adjusted. Paulson C. A. and J. J.
Simpson (1977) Irradiance Measurements in the Upper Ocean. Journal
of Physical Oceanography, 7, 952-956Barotropic Solution, Momentum Flux and DiffusionOceanThe HadCM3 model uses a standard "rigid-lid" barotropic
solution.ConvectionConvectionSchemeConvective mixing in the HadCM3 model uses the
Rahmstorf (1993) full convection scheme. The equation of state is
the UNESCO 1981 polynomial approximation. There are limits on the
model surface salinity which is not allowed to go outside the range
0 - 40 PSU. Rahmstorf, S. (1993) A
fast and complete convection scheme for ocean models. Ocean
Modelling, 101, 9-11.Mixed Layer SchemeMixedLayerSchemeHorizontal mixing of tracers uses a version of the
adiabatic diffusion scheme of Gent and McWilliams (1990) with a
variable thickness diffusion parametrization (Wright 1997;
Visbeck et al. 1997). There is no explicit horizontal diffusion
of tracers. The along-isopycnal diffusivity of tracers is 1000
m2/s and horizontal momentum viscosity varies with latitude
between 3000 and 6000 m2/s at the poles and equator
respectively. Near-surface vertical mixing is parametrized by a
Kraus-Turner mixed layer scheme for tracers (Kraus and Turner
1967), and a K-theory scheme (Pacanowski and Philander 1981) for
momentum. Below the upper layers the vertical diffusivity is an
increasing function of depth only. Convective adjustment is
modified in the region of the Denmark Straits and
Iceland–Scotland ridge better to represent down-slope mixing of
the overflow water, which is allowed to find its proper level of
neutral buoyancy rather than mixing vertically with surrounding
water masses. The scheme is based on Roether et al. (1994).
Gent P.R., and J.C.
McWilliams (1990) Isopycnal mixing in ocean circulation models.
Journal Physical Oceanography, 20, 150–155. Wright D.K., (1997) A
new eddy mixing parametrization and ocean general circulation
model. International WOCE News, 26, 27–29. Visbeck M., J.
Marshall, T. Haine, M. Spall (1997) On the specification of eddy
transfer coefficients in coarse resolution ocean circulation
models. Journal Physical Oceanography, 27, 381–402. Kraus, E. B. and J.
S. Turner (1967) A one-dimensional model of the seasonal
thermocline, Part II, Tellus, 19, 98-105.Pacanowski R.C., and
S.C. Philander (1981) Parametrization of vertical mixing in
numerical models of tropical oceans. Journal Physical
Oceanography, 11, 1443–1451. Roether W., V.M.
Roussenov, and R. Well (1994) A tracer study of the thermohaline
circulation of the eastern Mediterranean. In: Malanotte-Rizzoli
P, Robinson AR (eds) Ocean processes in climate dynamics: global
and Mediterranean example. Kluwer Academic, 371–394.
Salinity ControlOceanSalinity at every point is constrained to remain with
the limits 0 - 40 PSU. Some isolated basins reach these limits ;
keeping them there implies a small non-conservation of water
amounting to 0.2mm/year averaged over the ocean. Surface water
fluxes are converted to surface salinity fluxes using a constant
reference salinity of 35 PSU. Ocean StraitsOceanStraitSchemeMediterranean water is partially mixed with Atlantic
water across the Strait of Gibraltar as a simple representation of
water mass exchange at an overall level of 1 Sv. Similar
parameterisation applied to Hudson Bay. Sea IceCryosphereThe sea ice model, which is the same as that used in
HadCM2, uses a simple thermodynamic scheme and contains parametrisa-
tions of ice drift and leads (Cattle and Crossley 1995). A
parametrisation of ice concentration based on that of Hibler (1979) is
included. Ice concentration is not allowed to exceed 0.995 in the Arctic
and 0.980 in the Antarctic since completely unbroken ice cover is rarely
observed in reality even in pack ice. Ice forms predominantly by
freezing in the leads; it melts at the surface during summer and at the
base throughout the year. Ice depth can be increased by the formation of
`white ice' (Ledley 1985) where the weight of snow forces the ice-snow
interface below the water line.
The effect of sea ice formation
and melt on ocean salinity is accounted for within the model, assuming a
constant salinity of 0.6 parts per thousand for sea ice. Sublimation
increases ocean salinity, as the salt is assumed to blow into leads, and
white ice formation reduces it to account for the salt added in
converting snow to ice. Snowfall reduces ocean salinity in leads, and
accumulates onto ice, and all rainfall is assumed to reach the ocean
through leads. Cattle, H. and J. Crossley
(1995) Modelling Arctic climate change. Philosophical Transactions of
the Royal Society, London, A352, 201-213. . Hibler, W. D. (1979) A
dynamic-thermodynamic sea ice model. Journal of Physical Oceanography,
13, 1093-1104. Ledley, T. S. (1985) Sea
Ice: multiyear cycles and white ice. Journal of Geophysical Research,
90, 5676-5686. Sea Ice DynamicsCryosphereA simple parametrisation of sea ice dynamics based on
Bryan (1969) is also included. The windstress is applied to the
ocean beneath the ice. The ice thickness, concentration and snow
depth are advected using the top layer ocean current, using an
upstream advection scheme. Ice rheology is crudely represented by
preventing convergence of ice once the ice depth reaches 4 m (Steele
et al. 1997). The ice may become deeper than 4 m due to further
freezing. Del-squared horizontal diffusion of ice depth is also
applied, with a coefficient 2000 m2 s-1.
There is no
explicit representation of iceberg calving, so a prescribed water
flux is returned to the ocean at a rate calibrated to balance the
net snowfall accumulation on the ice sheets, geographically
distributed within regions where icebergs are found. In order to
avoid a global average salinity drift, surface water fluxes are
converted to surface salinity fluxes using a constant reference
salinity of 35 PSU. Bryan, K. (1969) Climate
and the ocean circulation III: The ocean model. Monthly Weather
Review, 97, 806-827. Steele, M., J. Zhang, D.
Rothrock, and H. Stern (1997) The force balance of sea ice in a
numerical model of the Arctic Ocean. Journal of Geophysical
Research, 102, 21 061 - 21 079. Sea Ice ThermodynamicsCryosphereThe thermodynamics of the sea-ice model is based on the
zero-layer model of Semtner (1976). Surface fluxes over the ice and
leads fractions of each grid box, and surface temperatures, are
calculated separately within the atmosphere component of the model,
assuming a linear temperature profile in the ice.
A
windmixing energy, used in the mixed layer model, is calculated
using the drag coefficient appropriate for leads and weighted by the
leads fraction of the grid square. Oceanic heat flux into the base
of the ice is related to the temperature difference between the
ocean top level and the base of the ice (assumed to be at freezing
point of -1.8 °C) with a coupling coefficient of 20 Wm-2 K-1.
Semtner, A. (1976) A
model for the thermodynamic growth of sea ice in numerical
investigations of climate. Journal of Physical Oceanography, 6,
379-389Sea Ice AlbedoCryosphereThe surface albedo is 0.8 at -10 °C and below, and
between -10 and 0 °C it falls linearly to 0.5. This parametrisation
aims to reproduce some of the effect of the ageing of snow, the
formation of melt ponds, and the relatively low albedo of bare ice.
events.Atmosphere to Ocean CouplerCouplerThe models are coupled once per day. The atmospheric model
is run with fixed SSTs through the day and the various forcing fluxes
are accumulated each atmospheric model time step. At the end of the day
these fluxes are passed to the ocean model which is then integrated
forwards in time. The updated SSTs and sea ice extents are then passed
back to the atmospheric model. As there are six ocean grid points to
every atmospheric grid point interpolation and/or averaging is used to
transfer fields between the two grids conserved.
River outflow
is also included allowing ocean salinity feedbacks via changes over
land. Runoff is converted into river outflow using river catchments over
land and associated coastal outflow points are defined relative to the
model grid. River transport is not modelled explicitly, so runoff is
transported instantaneously to the coast.Gordon, C., C. Cooper, C.A.
Senior, H.T. Banks, J.M. Gregory, T.C. Johns, J.F.B Mitchell and R.A.
Wood (2000) The simulation of SST, sea ice extents and ocean heat
transports in a version of the Hadley Centre coupled model without flux
adjustments. Climate Dynamics, 16, pp147-168.HadCM3 Climate Simulation - IPCC emission scenario SRES-B1NumSimwww.metoffice.gov.ukLINKHadCM3 configuration of the Unified Model Version
4.5.1This experiment produced model outputs reflecting the SRES-B1
emissions scenario - the lowest green house gas concentrations of the six
SRES scenarios. The experiment was restarted at 2014-11-01 to resolve an
error in the forcings.All anthropogenic forcing from multiple species of
greenhouse gases as defined for the IPCC SRESB1 emissions scenario,
sulfur (direct and indirect forcing, sulphur chemistry without natural
DMS and SO2 background emissions; anthropogenic SO2 emissions from
surface and high level only) and tropospheric/stratospheric ozone.
Experiment was initialised using one of the HadCM3 Historic
Anthropogenic Forcing run ensemble elements (run: abqzd - 1989-12-01).
UM Runid1989-12-01T00:00:002100-11-01T00:00:001989-12-01T00:00:002100-11-01T00:00:001859-12-01T00:00:001859-12-01T00:00:00SURFACE TEMPERATURE AFTER TIMESTEP001:00:024SURFACE ZONAL CURRENT AFTER TIMESTEP001:00:028SURFACE MERID CURRENT AFTER TIMESTEP001:00:029FRAC OF SEA ICE IN SEA AFTER TSTEP001:00:031SEA ICE DEPTH (MEAN OVER ICE) M001:00:032GEOPOTENTIAL HEIGHT: PRESSURE LEVELS001:16:202TEMPERATURE ON PRESSURE LEVELS001:16:203RELATIVE HUMIDITY WRT ICE ON P LVS001:16:204PRESSURE AT MEAN SEA LEVEL001:16:222U COMPNT OF WIND AFTER TIMESTEP12801:00:002V COMPNT OF WIND AFTER TIMESTEP12801:00:003THETA AFTER TIMESTEP12801:00:004SPECIFIC HUMIDITY AFTER TIMESTEP12801:00:010CONV CLOUD AMOUNT AFTER TIMESTEP12801:00:013CONV CLOUD LIQUID WATER PATH12801:00:016SNOW AMOUNT OVER LAND AFT TSTP KG/M212801:00:023SURFACE TEMPERATURE AFTER TIMESTEP12801:00:024BOUNDARY LAYER DEPTH AFTER TIMESTEP12801:00:025FRAC OF SEA ICE IN SEA AFTER TSTEP12801:00:031SEA ICE DEPTH (MEAN OVER ICE) M12801:00:032SULPHUR DIOXIDE EMISSIONS12801:00:058SO2 MASS MIXING RATIO AFTER TSTEP12801:00:101SO4 AITKEN MODE AEROSOL AFTER TSTEP12801:00:103SO4 ACCUM. MODE AEROSOL AFTER TSTEP12801:00:104SO4 DISSOLVED AEROSOL AFTER TSTEP12801:00:105HIGH LEVEL SO2 EMISSIONS KG/M2/S12801:00:126NET DOWN SURFACE SW FLUX: SW TS ONLY12801:01:201NET DN SW RAD FLUX:OPEN SEA:SEA MEAN12801:01:203NET DOWN SURFACE SW FLUX BELOW 690NM12801:01:204INCOMING SW RAD FLUX (TOA): ALL TSS12801:01:207OUTGOING SW RAD FLUX (TOA)12801:01:208CLEAR-SKY (II) UPWARD SW FLUX (TOA)12801:01:209CLEAR-SKY (II) DOWN SURFACE SW FLUX12801:01:210CLEAR-SKY (II) UP SURFACE SW FLUX12801:01:211SW HEATING RATES: ALL TIMESTEPS12801:01:232CLEAR-SKY SW HEATING RATES12801:01:233TOTAL DOWNWARD SURFACE SW FLUX12801:01:235NET DOWNWARD SW FLUX AT THE TROP.12801:01:237UPWARD SW FLUX AT THE TROP.12801:01:238NET DOWN SURFACE LW RAD FLUX12801:02:201NET DN LW RAD FLUX:OPEN SEA:SEA MEAN12801:02:203TOTAL CLOUD AMOUNT IN LW RADIATION12801:02:204OUTGOING LW RAD FLUX (TOA)12801:02:205CLEAR-SKY (II) UPWARD LW FLUX (TOA)12801:02:206DOWNWARD LW RAD FLUX: SURFACE12801:02:207CLEAR-SKY (II) DOWN SURFACE LW FLUX12801:02:208LW HEATING RATES12801:02:232CLEAR-SKY LW HEATING RATES12801:02:233NET DOWNWARD LW FLUX AT THE TROP.12801:02:237TOTAL DOWNWARD LW FLUX AT THE TROP.12801:02:238OZONE MASS MIXING RATIO AFTER LW12801:02:260HT FLUX THROUGH SEAICE:SEA MEAN W/M212801:03:201HT FLUX FROM SURF TO DEEP SOIL LEV 112801:03:202SURFACE HEAT FLUX W/M212801:03:217X-COMP OF SURF & BL WIND STRESS N/M212801:03:219Y-COMP OF SURF & BL WIND STRESS N/M212801:03:220SURFACE TOTAL MOISTURE FLUX KG/M2/S12801:03:223WIND MIX EN'GY FL TO SEA:SEA MN W/M212801:03:22410 METRE WIND U-COMP B GRID12801:03:22510 METRE WIND V-COMP B GRID12801:03:226SFC SH FLX FROM OPEN SEA:SEA MN W/M212801:03:228EVAP FROM OPEN SEA: SEA MEAN KG/M2/S12801:03:232SURFACE LATENT HEAT FLUX W/M212801:03:234SEAICE TOP MELT LH FLX:SEA MEAN W/M212801:03:235TEMPERATURE AT 1.5M12801:03:236SPECIFIC HUMIDITY AT 1.5M12801:03:237DEEP SOIL TEMPERATURE AFTER B.LAYER12801:03:238RELATIVE HUMIDITY AT 1.5M12801:03:245SURFACE SNOWMELT HEAT FLUX W/M212801:03:258CANOPY CONDUCTANCE M/S12801:03:259GROSS PRIMARY PRODUCTIVITY KG C/M2/S12801:03:261NET PRIMARY PRODUCTIVITY KG C/M2/S12801:03:262PLANT RESPIRATION KG/M2/S12801:03:263SO2 SURFACE DRY DEP FLUX KG/M2/S12801:03:270SO4 AIT SURF DRY DEP FLUX KG/M2/S12801:03:271SO4 ACC SURF DRY DEP FLUX KG/M2/S12801:03:272SO4 DIS SURF DRY DEP FLUX KG/M2/S12801:03:273EVAP FROM SOIL SURF : RATE KG/M2/S12801:03:296EVAP FROM CANOPY : RATE KG/M2/S12801:03:297SUBLIM. SURFACE (GBM) : RATE KG/M2/S12801:03:298LARGE SCALE RAINFALL RATE KG/M2/S12801:04:203LARGE SCALE SNOWFALL RATE KG/M2/S12801:04:204CONVECTIVE RAINFALL RATE KG/M2/S12801:05:205CONVECTIVE SNOWFALL RATE KG/M2/S12801:05:206CONV. CLOUD AMOUNT ON EACH MODEL LEV12801:05:212TOTAL RAINFALL RATE: LS+CONV KG/M2/S12801:05:214TOTAL SNOWFALL RATE: LS+CONV KG/M2/S12801:05:215TOTAL PRECIPITATION RATE KG/M2/S12801:05:216X COMPONENT OF GRAVITY WAVE STRESS12801:06:201Y COMPONENT OF GRAVITY WAVE STRESS12801:06:202LAND SNOW MELT HEAT FLUX W/M212801:08:202SOIL MOISTURE CONTENT12801:08:208CANOPY WATER CONTENT12801:08:209SOIL MOISTURE CONTENT IN A LAYER12801:08:223UNFROZEN SOIL MOISTURE FRACTION12801:08:229FROZEN SOIL MOISTURE FRACTION12801:08:230CANOPY THROUGHFALL RATE KG/M2/S12801:08:233SURFACE RUNOFF RATE KG/M2/S12801:08:234SUB-SURFACE RUNOFF RATE KG/M2/S12801:08:235BULK CLOUD AMOUNT AFTER MAIN CLOUD12801:09:201CLOUD LIQUID WATER AFTER MAIN CLOUD12801:09:206CLOUD ICE CONTENT AFTER DYNAM CLOUD12801:09:207ATMOS ENERGY CORR'N IN COLUMN W/M212801:14:201U WIND ON PRESSURE LEVELS B GRID12801:15:201V WIND ON PRESSURE LEVELS B GRID12801:15:202GEOPOTENTIAL HEIGHT: PRESSURE LEVELS12801:16:202TEMPERATURE ON PRESSURE LEVELS12801:16:203RELATIVE HUMIDITY WRT ICE ON P LVS12801:16:204PRESSURE AT MEAN SEA LEVEL12801:16:222SURFACE HEAT FLUX W/M219201:03:217X-COMP OF SURF & BL WIND STRESS N/M219201:03:219Y-COMP OF SURF & BL WIND STRESS N/M219201:03:220SURFACE TOTAL MOISTURE FLUX KG/M2/S19201:03:223SPECIFIC HUMIDITY AFTER TIMESTEP217601:00:010CLOUD LIQUID WATER AFTER MAIN CLOUD217601:09:206CLOUD ICE CONTENT AFTER DYNAM CLOUD217601:09:207Indicator of local q diffusion217601:13:201TEMPERATURE AT 1.5M409601:03:236TEMPERATURE AT 1.5M819201:03:236BADC2007-02-01PPNetwork99Data Extraction Completed2008-02-01T00:00:00Data Transfer Completed2008-02-01T00:00:00Closed: Request Fulfilled